1. Field of the Invention
The present invention relates to a control apparatus for an automobile air-conditioner having a cooled air bypass passage for supplying cooled air to a vent outlet independently of a main airflow passage.
2. Description of the Prior Art
A cooled air bypass passage for supplying cooled air to a vent outlet is provided for controlling the temperature of air in the vicinity of the driver's head without exerting any influence upon the temperature control in the vicinity of the driver's feet, thereby providing a comfortable air-conditioning in which the head is kept cool while the feet are kept warm. According to a conventional control of the bypass passage, such as that shown in Japanese Patent Laid-open Publication No. 57-7714, for example, the bypass passage is shifted from the fully closed state to the full open state when the temperature of the upper part of a vehicle compartment exceeds the temperature of the lower part by a predetermined value, or when the radiant heat of the sun exceeds a predetermined value.
As described above, in the conventional control system, the supply of cooled air through the bypass passage is controlled based on the temperature difference between the upper and lower portions of the vehicle compartment or the radiant heat of the sun. This means that the full opening of the bypass passage for supplying cooled air is achieved based upon such a prediction that an increase of each control factor beyond the respective predetermined value necessarily causes a temperature rise in the upper part of the vehicle compartment. Such a conventional control based on the prediction does not guarantee a comfortable air conditioning effect in the vicinity of the driver's head.